…thoughts from the Garden

Monthly Archives: February 2011

The Horridge Conservatory features a Bog Garden with a unique collection of carnivorous plants. These plants have the specialized ability to trap and digest invertebrates of various kinds, mostly insects ( although some large tropical specimens are said to be capable of digesting frogs, mice, rats, and bats….) These insect-eating beauties evolved in environments where nutrient concentrations are low but water and sunshine are seasonally abundant, such as bogs and swamps.

Sarracenia purpurea, the Pitcher Plant

There are different mechanisms for insect-trapping if you’re a plant. One, used by the Pitcher Plants, is to have a chamber full of enticing liquid for the poor bug to drown in and then be digested. Another is to have glandular hairs on stalks with very sticky droplets on them. The Sundews use this method to capture their prey, which is then digested when the glands produce digestive enzymes. A third method is used by Venus Fly Traps, which is possibly most like the Creature: Near the crease where the two leaf “jaws” join there is a series of tiny hairs. If an insect walks across these hairs, touching two or more of them in succession, the leaf will close quickly enough to prevent its escape. The insect is then slowly digested and absorbed by the leaf.

Drosera capensis, the Cape Sundew

The Bog Garden has both native and exotic carnivorous plants. There are Sarracenias, Pitcher Plants that are native to the Southeastern US, along with many beautiful hybrid Sarracenias, in different colors and sizes. There are also Nepenthes, the tropical Pitcher Plants. Some of these are on loan from a student here at URI — thanks, CJ! There are Butterworts (Pinguicula species), which trap insects with sticky hairs along the leaves and s-l-o-o-o-w-l-y roll the leaf around the insect and digest it. The Venus Fly Trap, Dionaea muscipula, is the only species of its genus and native to the Southeastern US. It continually flowers and re-seeds in the Bog.

Nepenthes hybrid 'Judith Finn', the Tropical Pitcher Plant

Some of the carnivorous plants are easy to grow and make interesting houseplants! Yes, you can feed them insects, but it is better not to trigger trapping mechanisms, unless you actually have food for them. Otherwise, they are expending a huge amount of physiological energy for no gain, and that will weaken them.

I enjoy observing the carnivorous plants even when they are not dining. Their unusual forms are intriguing and make them a great subject for photos and drawings. In fact, there are some beautiful botanical drawings of Pitcher Plants in our Hallway Gallery. For more information, the New England Carnivorous Plant Society, which generously donated many plants to the Conservatory Bog, has a great informative website, http://www.necps.org, AND a Carnivorous Plant Show in the fall. Happy Hunting!

The ‘Lady Margaret’ Passionflower blooming now is a gorgeous deep red with a white center. Passionflowers are an interesting combination of delicate petals and filaments topped by the very architectural structure of the stamens. Or, as the Missouri Botanical Garden website says, “The hallmark of the family is the corona… filaments that extend outward like a cup. The corona…carries perfume, holds in nectar, acts as a landing platform for pollinators, and is a visual attractant. In Passiflora, the stamens are borne beneath the ovary on an elevated column”.

Passiflora is a genus of about 500 species worldwide, mostly vines. There are nine species native to North America, with a few being much cold-hardier than you would think from their tropical appearance. P. incarnata, also known as Maypop, can be grown outdoors in zone 5. P. lutea and P. caerulea are also considered cold hardy enough to grow outdoors in southern Rhode Island.

Lady Margaret was given to me by a plant person who knows her plants, and I’m sure it is a Lady Margaret. Unfortunately, I didn’t get the species or hybrid name, and a quick internet search came up with lots of possibilities: Passiflora vitifolia x P. caerulea﻿, Passiflora coccinea x P. incarnata, Passiflora caerulea ‘Constance Eliott’ x P. miniata, Passiflora incarnata x P. miniata, and Passiflora coccinea x P. caerulea. It will take a little more detective work to figure this one out !

I did look into the common name Passionflower, which doesn’t refer to the Valentine’s Day passion of love. Too bad, because I think they’re more interesting than red roses! The word passion is sometimes used to mean suffering, and 15th and 16th century Spanish Christian missionaries viewed the unique physical structures of this plant as symbols of the last days of Jesus and his crucifixion. In different parts of the world, Passionflowers have reminded people of other things, such as clocks: it’s Clock-flower in Hebrew and Clock-plant in Japanese.

Passiflora incarnata (not my Lady Margaret) has been used as a medicinal plant for centuries. The University of Maryland Medical Center (www.umm.edu/altmed/articles/passionflower-000267.htm) says a tea of the flowers, leaves, and stems was used traditionally in the Americas and later in Europe as a “calming” herb for anxiety, insomnia, seizures, and hysteria. It is still used today to treat anxiety and insomnia.

Passiflora incarnata, Purple Passionflower

Passionflowers in their native habitats are an important source of food for a variety of creatures. Some are pollinated by hummingbirds, wasps, bumblebees, or bats looking for nectar. Larvae and caterpillars of a wide variety of butterflies feed on the leaves. Some Passifloras, such as P. edulis, are cultivated for their fruit by people of the Caribbean.

Cuttings are the easiest way to propagate Passionflowers. Cuttings taken in the spring and kept close to 65 F will root readily in a 50/50 mix of peat and perlite. They’re not hard to grow, preferring well drained soil and full sun. The root systems are relatively small, so they can be grown indoors without the need for a huge pot.

Ahhh! In spite of the snow/cold/rain/thaw the Witchhazel is flowering right on time. On Upper College Road, the cultivar ‘Jelena’ is beginning to open with red and orange flowers that always remind me of “blow-out” party favors. Over near the gazebo, ‘Arnold Promise’, from the Arnold Arboretum, has yellow flowers and a pleasing fresh light scent. The very tips of the yellow petals are just beginning to peek out from the buds.

“Jelena and ‘Arnold Promise’ are both cultivars of Hamamelis x intermedia, a cross between Hamamelis mollis, the Chinese Witchhazel, and Hamamelis japonica, Japanese Witchhazel. There is also a Witchhazel native to Eastern North America: Hamamelis virginiana, which blooms in late fall. Its yellow flowers have a slight fragrance. Hamamelis vernalis is native to central North America. It begins flowering in late winter or early spring with fragrant yellow and red flowers.

All the witchhazels are shrubs or small trees, growing to about 12 feet tall at the most. Although mainly the cultivars are sold and planted, they all make wonderful additions to the home landscape. I would plant them solely for the fact that they flower in winter. (It’s certainly not early spring yet!) The added bonus is that Witchhazels also have nice yellow autumn foliage and are for the most part insect and disease free.

Witchhazel is also known as a medicinal plant. An extract is distilled from the twigs and used as an astringent for insect bites, poison ivy, and other skin irritations. I just found out that almost all the Witchhazel extract sold in the United States today is manufactured by one company and most of the harvest is from northwestern Connecticut. Who would have guessed!

So on a “thaw” day like today (44 degrees!) take a walk and keep your eyes open for those narrow, crinkly petals suspended on bare branches. Whether it’s a native or a well-adapted cultivar, Witchhazel flowers in February lift my spirits with thoughts of spring.